The present invention is directed to a fixing device or coupling. The fixing device or coupling is usable for connecting two components that can be displaced with respect to each other in an adjusting device.
A plurality of rollers are typically provided in conventional printing presses, such as web-fed rotary printing presses. Inking rollers in particular are provided, and are used for transferring ink from an ink reservoir to the plate cylinders of the printing press. It is possible to meter the amount of ink which is transferred to the plate cylinders by use of the inking rollers, so that the ink is transferred in the form of a uniform film of defined thickness. It is possible to compensate for interferences, such as speed fluctuations and rotary oscillations, by the utilization of the metering capabilities of the inking rollers.
Dampening rollers can also be provided in the printing press. These dampening rollers typically transfer a dampening agent, for example water, to the printing group.
Roller pairs are often formed by rollers, which are in engagement with each other, and in which at least one of the rollers has a cylinder surface made of an elastic material. This elastic or resilient cylinder surface can be deformed, at least slightly, by the contact pressure of the opposite roller. The result of the elastic deformation of the roller surface is a contact area which extends in a straight line between the rollers and which is called a contact strip. The width of the contact strip can be varied by setting the contact pressure between the rollers. The width of this contact strip has a considerable effect on the result of the printing. If, for example, the contact strip in an inking unit is too narrow, not enough ink is transferred. In those cases in which the contact strip is too wide, the elastic roller can be damaged by flexing occurring because of the excess contact pressure.
In order to be able to correctly set the strip width, in particular as a function of the respective operating conditions, for example as a function of the temperature of the printing press, or the amount of its wear, it is necessary to support at least one roller of the pair adjustably, so that the adjustably supported roller can be pushed with an adjustable force by an actuator in the direction of the opposite roller. Once the correct contact pressure between the two rollers has been established, a fixing device or coupling which is usable for securing the first roller in place, with respect to the second roller, is operated for permanently maintaining the contact pressure.
A device for setting the contact pressure between two rollers is known from DE 197 19 305 A1. In the seating arrangement described in that document, the adjustably supported roller is pushed against the opposite roller by a spring which is supported on the frame of the printing press. A defined contact pressure between the two rollers, as a function of the respectively selected characteristic spring curve, always occurs because of the use of such a spring. A clamping mechanism with a clamping lever and a clamping plate for fixing the roller in the position where it is pressed against the other is described, by use of which the roller shaft can be fixed in place on the frame by a frictional connection.
A device for the semi-automatic adjustment of rollers is known from DE 199 19 733 A1. In this device, the adjustably seated roller is maintained in a roller support, which, in turn, is seated on a frame support that is arranged, fixed in place, on the frame. In this case, the roller support and the frame support can be adjusted in relation to each other and are connected with each other by resilient springs. The resilient springs are provided with a defined prestress, so that the roller, which is adjustably seated on the roller support, can be pressed against the opposite roller with a defined contact pressure. Arresting bolts, by use of whose feed movement the roller support can be frictionally clamped to the frame support, are provided for arresting the roller support on the frame support.
DE 42 31 673 A1 describes a device for roller adjustment. A roller is first displaced in a radial direction by use of a pressure chamber and thereafter is fixed in place.
DE 30 46 989 C3 discloses a device for bringing an impression cylinder into a printing or non-printing position. In the course of this movement, the rotary movement of a synchronous spindle is fixed by a multiple disk brake.
The object of the present invention is directed to providing a fixing or coupling device.
In accordance with the invention, this object is attained by providing a fixing device or coupling usable with at least two components which can be displaced with respect to each other in an adjusting device. One element of the coupling is connected with one component and at least another element is connected with the second component. The two elements can be brought into a fixing or locking engagement with each other by friction. The coupling has a plurality of interengaging lamella elements which are alternatingly connected to the first and second elements of the fixing or coupling device. Each lamella has a friction face that is engageable with a friction face of an adjacent lamella element. The lamella elements can be clamped against each other. The lamella element can be moved in relation to each other in a translatory manner in a plane defined by the friction faces.
The advantages obtainable by the present invention consist, in particular, in that such a fixing or coupling device can be produced in an extremely compact and therefore space-saving manner. This is achieved in that, for fixing the displaceable components in place in relation to each other, several lamella elements are frictionally clamped. By arranging several, and in particular a multitude of such lamella elements one behind the other, the frictional force required for fixation is distributed over a multitude of frictional faces between the multitude of lamella elements. By clamping the lamella elements arranged one behind the other, the clamping face acts oppositely at all frictional faces.
Suitable lamella elements, which are usable in the subject fixing or coupling device, are known, for example, from lamella couplings which are employed for the frictional connection of rotatably seated shafts. In contrast to previously known lamella couplings, the lamellas of the present invention are displaceable in respect to each other in the fixing or coupling device in at least one direction and can be displaced within a defined adjusting range, depending on the play between the components of the fixing device, and can thereafter be fixed in place. The adjusting movement therefore does not take place in the manner of a pivoting or of a rotary movement, as in connection with the prior lamella coupling, but takes place in the manner of a translatory movement in the plane defined by the orientation of the frictional faces of the lamella elements.
Basically all elements or structures can be used as the clamping device, by use of which the lamellas can be clamped to each other by the exertion of a sufficient contact pressure. It is particularly advantageous for the clamping device to be designed in the manner of a prestressed spring element. In the position in which the fixing device or coupling is fixed in place, a spring force of such a size is exerted on the lamella elements by the prestressed spring element, that they are dependably fixed against each other by a frictional connection. An unintentional release of the fixing device, for example in the case of the loss of an energy supply, occurrence which raises a serious concern in connection with other clamping devices, is prevented because of this. For releasing the clamping device to accomplish an adjusting the components of the fixing device or coupling, it is necessary, in this embodiment of the present invention, to provide an actuator at the fixing device, by use of which actuator the spring element can be compressed to such an extent that the lamella elements can be relaxed, and therefore can be displaced with respect to each other.
In principle, any desired drive mechanisms can be employed for use in actuating the spring elements. For example electrically, hydraulically or pneumatically operating systems can all be used. It is particularly advantageous for the actuator to be configured in the manner of a punch, which is displaceably arranged in a pressure chamber. By charging the pressure chamber with a pressure medium, such as, for example, compressed air or hydraulic fluid, the punch can be displaced against the spring force of the spring element, so that the lamella elements are relaxed as a result of this punch displacement.
An advantage of the arrangement for setting the contact pressure between rollers in accordance with the present invention moreover lies in the very compact structure, which is made possible by the contemplated construction. As known from the prior art, one roller of a roller pair is typically fastened on a roller support, which, in turn, is displaceably maintained on a frame support. In turn, the frame support can either be fastened fixed in place on the frame of the printing press or, alternatively, the frame support can be supported on appropriate actuating devices which are used, for example, for placing the roller that is maintained in the support in contact with or out of contact from the oppositely located roller.
A recess is provided on the roller support, or on the frame support, which recess is engaged by a section of the frame support, or of the roller support. The dimensions of the section or of the recess have been selected to be such that a gap is formed between the recess and the section, by use of which gap, the adjustment range between the roller support and the frame support is defined. The roller support can be displaced relative to the frame support inside this gap. In order to be able to provide the adjusting force required for the adjusting movement, or in order to be able to press the first roller against the oppositely located roller with a defined contact pressure, at least one actuator is arranged in the gap, which at least one actuator exerts a pulling and/or a pressure force on the roller support, in the process of which, the roller support is supported on the frame support. Extremely compact components can be provided by reason of the arrangement of the actuator in the gap between the roller support and the frame support. In this context, it is not significant whether the recess is provided on the frame support or on the roller support, so that in principle, both configurations are alternatively capable of being used.
The shape of the recess and of the section engaging it basically can be as required, and can be matched to the respective intended use. It is thus possible for the recess to be embodied right-angled and having a play, in respect to the section engaging it, in only one direction. As a result, the roller support can only be displaced in one adjusting direction. However, if selective displacement of the roller support in different directions is desired, for example because the roller seated in the roller support must be selectively placed against several rollers, it is particularly advantageous if both the recess and the section are rotationally symmetrical, so that a revolving gap is formed between them. It is possible, because of this, to allow the roller support to be displaced in the adjusting plane in different adjusting directions in relation to the frame support. The adjusting range of the adjusting movement is limited by the width of the revolving gap.
If the roller support can be adjusted in different adjusting directions in relation to the frame support, for example over an entire adjusting plane, several actuators are required for providing the needed adjusting movement. Thus, in accordance with a preferred embodiment of the present invention, at least three actuators are arranged in the gap between the roller support and the frame support. The roller can be pushed in respectively different directions. By an appropriate selection of the forces exerted by the respective actuators, it is possible to exert a resultant force directed in any desired direction on the roller support, and therefore on the roller seated in the roller support, by the combined control of the different actuators. In this case, the actuators are preferably distributed in a star pattern in the gap between the roller support and the frame support. If four actuators are arranged opposite each other in the gap, it is possible to dependably prevent the tilting of the actuators, since by operation of the drive mechanism of one actuator the respectively oppositely located actor is compressed.
How the actuators are constructed is, in principle, widely selectable. Thus, electrically or piezo-electrically operating systems are possible. It is particularly advantageous if the actuator is embodied in the manner of a pressure element, which can be charged by a pressure medium. If a hydraulic oil is used as the pressure medium, it is possible by to apply very high pressures with correspondingly great adjusting forces.
In accordance with a preferred embodiment of the present invention, a precompressed gas, and in particular compressed air, is used. Since gases are compressible, an elastic spring effect results from the use of a precompressed gas and acts between the frame support and the roller support. By use of this spring effect it is possible to compensate for mechanical disturbances caused, for example, by unbalanced masses or out-of-round conditions. Furthermore, compressed air as an energy transfer source is available in most printing presses.
The arrangement for adjusting the contact pressure between the displaceably seated roller and an oppositely located roller can also be used for placing the displaceably seated roller into contact or out of contact with the other roller. For this purpose, it is necessary to select the adjusting range between the frame support and the roller support to be sufficiently large to be able to perform the adjusting movement necessary for the removal of the one roller out of contact with the other. Furthermore, for performing such an adjusting movement, the actuator between the frame support and the roller support must be suitably selected. To be able to perform the placement into and out of contact independently from the actuation of the arrangement, it is advantageous for the arrangement to be fastened on an additional out-of-contact device. For example, this out-of-contact device can be embodied in the manner of a pivot arm, by use of which the frame support can be pivoted in relation to the frame of the printing press between a contact position and an out-of-contact position.
The compactness of the device, as a whole, can be further increased by arranging a fixing device in an arrangement for adjusting the contact pressure between two rollers.
To this end, it is particularly advantageous if the fixing device extends along the center axis of the device coaxially in respect to the longitudinal axis of the roller seated on the roller support.